With murder rising, the homeless population mushrooming and the quality of life taking a beating, New Yorkers wanting help will need plenty of luck getting Bill de Blasio’s attention. They might also need a plane ticket to track down out-of-town Bill.

With trips to Iowa, Nebraska, California, Puerto Rico and other points, Mayor Putz already has spent more than a month on the road this year. He goes to Washington more often than Staten ­Island.

It’s not just his body that’s missing in action — it’s his attitude, too. His withering broadside against Gov. Andrew Cuomo, where he accused his fellow Democrat of ­carrying out “a vendetta,” was a burn-the-bridges event. On his next visit to Albany, he’ll probably be greeted by a locked door. That won’t help the city.

The mayor pitched his tirade on the eve of an eight-day vacation to the Southwest, where he griped about his job to other mayors.

Before that, he griped to Rolling Stone magazine that Gotham doesn’t appreciate him, while people across the country “understand” his achievements “better than people in New York City.”

If that’s true, de Blasio can cancel his plan to hire an aide to push his agenda around the country and “change the dynamic in Washington.”

The pattern suggests that while neglecting the job he has, de Blasio wants a job nobody elected him to: Running America.

Here’s a modest proposal, mayor: Get your head out of the clouds, your feet on the ground and your hands dirty — before the city goes to hell on your watch.

New York history is clear: Successful mayors are workhorses. Failed mayors fancy themselves as show horses, and end up as horse’s asses.